The invention relates to a device for sealing a gap between at least two components or groups of components which are arranged to be movable with respect to one another, particularly of a heat exchanger, in which a strip-shaped sealing body which is connected with the one component is sealingly and movably guided in a groove of the other component.
Difficulties arise, for example, in the case of internal-combustion engines, gas turbines, jet engines or heat exchangers, with respect to sealing off, in a comparatively simple and reliable manner, gaps through which a hot liquid, such as gas, flows. In particular, this is so because the mutually adjacent components which form the gap are subjected to different thermally caused expansions as well as spatially different motions which may result from shock loads, among others.
The German Patent Document DE-OS 35 14 377 concerns solutions for the discussed problem in the case of a heat exchanger of a cross-counterflow construction which has essentially parallel collecting pipes for the supply of compressed air into a tube matrix and the removal of compressed air from a tube matrix which consists of U-shaped profile tubes, and also has a casing surrounding the matrix for the purpose of a hot gas flow through the matrix. In a first version of the known case, a gap between mutually adjacent components (guide wall of the tube matrix/casing) is to be bridgeable with respect to supplied hot gas by means of a motion compensating differential pressure seal. In this case, a thin sheet metal strip or a foil is to be provided which is fastened to the casing (first component) and which is to engage with axial and radial play in a groove connected with the guide wall (second component, for example, "shell"), the groove being formed of a fork-shaped support. Exclusively as a function of the existing differential pressure, the thin strip, for example, is to fit snugly in a sealing manner against an inner groove flank. A significant disadvantage of this solution is the fact that the sealing effect will fail in cases in which there are virtually no or comparatively low pressure differences. Another disadvantage of this first sealing version of the known case is the one-sided component-related rigid connection and construction of the strip-shaped sealing element. Thus, the sealing element itself is not constructed to be compatible with respect to heat and motion. The spatial motion-compensating degree of freedom of this sealing concept is therefore comparatively severely limited. In a second sealing version of the known case, instead of the differential pressure seal (strip, foil), a brush seal is to be arranged in the concerned gap, in the case of which one set of free ends of the bristles are to movably engage in the groove while the bristles are locally compressed. This known concept has the significant disadvantage of comparatively high manufacturing expenditures of the brush seal (bristle packing) as well as a wear caused by friction and temperature influences which starts relatively early. By itself, this known concept is also known from the German Patent Document DE-OS 35 14 382.
The invention is based on the object of providing a seal according to the initially mentioned type which has low wear and is reliable irrespective of existing differential pressures, particularly in view of operationally caused comparatively severe mutual spatial component movements and displacements at the gap to be sealed.
The concerned object is achieved according to the invention by a device for sealing a gap between at least two mutually movable components, comprising a seal secured to one of the at least two components and being guided movably and sealingly in a groove in the other component, wherein said seal is formed of plate-like elements, said plate-like elements are arranged movably in a longitudinal direction of said gap and are freely expandable, wherein said plate-like elements are suspended to pivot on said one component, and a clamping device for movably holding said plate-like elements on said other component.
It is therefore achieved that a cost-effective, reliably operating seal is provided, particularly with respect to hot gas, and specifically also in all cases in which relatively high deviations occur from the desired gap geometry. This is achieved even in relation to relatively large mutual component displacements with respect to the normal position which occur in all three directions in space. In this case, the sealing body may be constructed to be movable in the longitudinal direction of the gap, or individually movable in itself and compatible with respect to thermally caused expansions, which, among other facts, is achieved by way of the mutual distance gaps between adjacent borderings of the skinplates. According to the invention, the sealing body may also be interpreted to have the shape of a shingle with two or several layers. At least a double-layering of the elements or metal sheets ensures a mutual and tight bridging of the distance gaps which is offset in the longitudinal direction of the gap.
The spring-type embracing of the end of the sealing body which faces one component side has, among others, the following important advantages: A perfect sealing, specifically, irrespective of the differential pressure, also in the case of a relatively extensive relative component offset, transversely to the dimension of the width of the gap to be sealed. A "spring pliers construction" (wall segment) of the groove on at least one side ensures the sealing absorption of a combined sliding and swivelling motion of the sealing body. In this case, the swivel motion is promoted by the hook suspension which relates to the component on one side and which, in turn, permits the displacement of the elements or of the sealing body in the longitudinal direction of the gap. At the same time, the groove is capable of receiving the "plate structure" composed of individual elements in a motion compensating manner in the longitudinal direction of the gap. The spring-type embracing of the sealing body at the groove results in a mutual holding-together of the individual elements or metal sheets without the requirement of first relying on local mutual fixing points of the metal sheets or plates.
Advantageous developments of the invention are found in claims 2 to 13. The invention will be explained by means of examples illustrated in the drawings.